The 64bit version has two versions of regedit.
BACK UP YOUR REGISTRY FIRST!
1.) Enter into Start>Run: %systemroot%\syswow64\regedit
2.) Go to: HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows \ CurrentVersion
3.) Change the Path in DWORDs ProgramFilesDir, ProgramFilesDir (x86), ProgramW6432Dir to the new path, probably just changing the drive letter.
Make sure you create and copy over the files for both the 32 and 64 bit folders.
when you say "Make sure you create and copy over the files for both the 32 and 64 bit folders.", what exactly do we do here? just copy and paste both Program Files folders?